
Now the proof proceeds exactly as in [1]}. Assume that \(\theta \)  is an attractor stability condition, hence a small deformation of the self-stability condition \(\langle -,\gamma \rangle \) 
for some dimension vector \(\gamma \ne (n,n,n)\) .
Then \(\theta _1<0\)  implies that \(n_1\ge n_2\) , and \(\theta _3>0\)  implies that \(n_3\ge n_2\) : hence \(6n_3n_1\ge 2n_3n_2+2n_2n_1+2n_1n_3\) , and then, using (REF ):
\(\begin{aligned}q(\gamma ){} &\frac{1}{2}((n_1-n_2)^2+(n_2-n_3)^2+(n_3-n_1)^2)=n_1^2+n_2^2+n_3^2-n_1n_2-n_2n_3-n_3n_1\\\le {} & n_1^2+n_2^2+n_3^2-3n_1n_2-3n_2n_3-3n_2n_3+6n_3n_1\le 1\end{aligned}\) 
